I thought the conclusion was satisfying (but perhaps not worth a 20-year wait)

Stephen King, write an underwhelming ending? Never! ;) I'll have to check out the first novel, though, now that you've put it that way.

Here's a link (http://www.comicbookresources.com/?page=article&id=16631) to a story about the project. It's got some Randal Flagg artwork that's pretty good. I'm pretty excited about it myself.